Breno Quintella Farah

Heart rate variability and its relationship with central and general obesity in obese normotensive adolescents

ABSTRACT Objective: To analyze the relationship between the heart rate variability parameters and the indicators of central and general obesity in obese normotensive adolescents. Methods: Seventy-four 13 to 18 year-old obese normotensive adolescents participated in this study. The indicators analyzed for central and general obesity were waist circumference and body mass index, respectively. Heart rate variability was obtained by heart rate monitoring. For this, the adolescents remained in a supine position for 7 minutes with controlled breathing. Parameters were obtained in time domain (standard deviation of all the RR intervals, root mean square of successive differences between the normal adjacent RR intervals and the percentage of adjacent intervals with more than 50ms) and frequency domain variables (low and high frequency bands and the sympathovagal balance). Results: After adjustments for gender, age, and cardiorespiratory fitness, a negative correlation between the waist circumference and the root mean square of successive differences between the normal adjacent RR intervals (ß=-1.51; standard error=0.56; p<0.05) and the percentage of adjacent intervals with more than 50 ms (ß=-0.96; standard error=0.34; p<0.05) were observed, while the body mass index showed no significant correlation with any heart rate variability parameter (p>0.05). Conclusion: Central obesity is a better discriminator than general obesity of autonomic cardiac dysfunction in obese normotensive adolescents

Predictors of walking capacity in peripheral arterial disease patients

OBJECTIVE: To estimate walking capacity in intermittent claudication patients through a prediction model based on clinical characteristics and the walking impairment questionnaire. METHODS: The sample included 133 intermittent claudication patients of both genders aged between 30 and 80 years. Data regarding clinical characteristics, the walking impairment questionnaire and treadmill walking test performance were obtained. Multiple regression modeling was conducted to predict claudication onset distance and total walking distance using clinical characteristics (age, height, mass, body mass index, ankle brachial index lower, gender, history of smoking and co-morbid conditions) and walking impairment questionnaire responses. Comparisons of claudication onset distance and total walking distance measured during treadmill tests and estimated by a regression equation were performed using paired t-tests. RESULTS: Co-morbid conditions (diabetes and coronary artery disease) and questions related to difficulty in walking short distances (walking indoors – such as around your house and walking 5 blocks) and at low speed (walking 1 block at average speed – usual pace) resulted in the development of new prediction models high significant for claudication onset distance and total walking distance (p<0.001). In addition, non-significant differences from the results obtained by the treadmill test and estimated by the current model (p>0.05) were observed. CONCLUSION: The current study demonstrated that walking capacity can be adequately estimated based on co-morbid conditions and responses to the walking impairment questionnaire.

Intra-individuals and inter- and intra-observer reliability of short-term heart rate variability in adolescents

To examine the reliability of heart rate variability (HRV) parameters in adolescents and to analyse the inter‐ and intra‐observer reliability of data analysis.

Stages of health behavior change and factors associated with physical activity in patients with intermittent claudication

OBJECTIVE To analyze, in people with intermittent claudication, the frequency of individuals who are in each of stages of health behavior change to practice physical activity, and analyze the association of these stages with the walking capacity. METHODS We recruited 150 patients with intermittent claudication treated at a tertiary center, being included those > 30-year-old-individuals and who had ankle-arm index < 0.90. We obtained socio-demographic information, presence of comorbidities and cardiovascular risk factors and stages of health behavior change to practice physical activity through a questionnaire, they being pre-contemplation, contemplation, preparation, action and maintenance. Moreover, the walking capacity was measured in a treadmill test (Gardner protocol). RESULTS Most individuals were in the maintenance stage (42.7%), however, when the stages of health behavior change were categorized into active (action and maintenance) and inactive (pre-contemplation, contemplation and preparation), 51.3% of the individuals were classified as inactive behavior. There was no association between stages of health behavior change, sociodemographic factors and cardiovascular risk factors. However, patients with intermittent claudication who had lower total walking distance were three times more likely to have inactive behavior. CONCLUSION Most patients with intermittent claudication showed an inactive behavior and, in this population, lower walking capacity was associated with this behavior.

Percepção de estresse: associação com a prática de atividades físicas no lazer e comportamentos sedentários em trabalhadores da indústria

The aim of this study was to analyze the prevalence and the association between physical activity and sedentary behaviors with higher perceived stress in industrial workers. For this purpose, we used a cross-sectional design in which participants were selected using a 2-stage sampling process among industrial workers in Pernambuco state (northeast of Brazil). Data were obtained by using a previously validated questionnaire (Lifestyle and Leisure Habits of Industrial Workers). Higher perceived stress was referred by 13.2% and 45.2% were inactive during leisure-time. The prevalence of workers who reported spending >2 hours/day watching television was 31.8% and 57.4%, respectively, in week and in weekend days. It was observed, among men, a positive association between the TV-watching hours in week days with a higher perceived stress. It was concluded that the likelihood of referring higher perceived stress was greater among men exposed to sedentary behavior.

Low-intensity resistance exercise does not affect cardiac autonomic modulation in patients with peripheral artery disease

OBJECTIVE: To analyze the effect of a single bout of resistance exercise on cardiac autonomic modulation in patients with peripheral artery disease. METHODS: Fifteen patients with peripheral artery disease (age: 58.3±4.0 years) underwent the following sessions in a random order: resistance exercise (three sets of 10 repetitions of the six resistance exercises with a workload of 5–7 in the OMNI-RES scale) and control (similar to the resistance session; however, the resistance exercises were performed with no load). The frequency domain (low frequency, high frequency and sympathovagal balance) and symbolic analysis (0V, 1V and 2V patterns) of heart rate variability were obtained before and until one hour after the interventions. RESULTS: After the resistance exercise and control sessions, similar increases were observed in the consecutive heartbeat intervals (control: 720.8±28.6 vs. 790.9±34.4 ms; resistance exercise: 712.9±30.1 vs. 756.8±37.9 ms; p<0.05) and in the pattern of the symbolic analysis with no variation (0V) (control: 25.1±3.5 vs. 33.4±4.1%; resistance exercise: 26.1±3.2 vs. 29.7±3.5%; p<0.05) until 50 min after both interventions. The pattern of two variations (2V) decreased similarly (control: 11.2±2.1 vs. 8.3±2.1%; resistance exercise: 9.5±1.7 vs. 7.8±1.7%; p<0.05). In contrast, the pattern of one variation (1V), the low and high frequency bands and sympathovagal balance did not change after the interventions (p>0.05). CONCLUSION: A single bout of resistance exercise did not alter cardiac autonomic modulation in patients with peripheral artery disease.

Tempo de incidência dos gols no Campeonato Brasileiro de Futebol 2008

The aim of this study was to analyze the incidence time, origin and place of the goals of the 2008 Brazilian Championship, and to verify the influence of these parameters in the final classification. Data collection was performed by two independent evaluators that classified the goals according to the time of incidence, origin (stationary ball or ball rolling), and place of conclusion (inside or outside the area). A total of 1034 goals were scored. It was verified that there were more goals in the second half of the game (579 goals, ~56%), mainly in the last fifteen minutes (221 goals, ~21%). In all periods of the game, most of the goals were scored with the ball rolling and were performed inside the area. The results of the present study show higher incidence of goals at the end of the matches. The best ranked teams showed greater regularity in the distribution of goals between the intervals than the other teams.El objetivo de este estudio fue analizar el tiempo de incidencia, la origen y el lugar de los goles del Campeonato Brasileno de Futbol del 2008, y para comprobar la influencia de estos parametros en la tabla de posiciones. La recogida de datos se realizo por dos evaluadores independientes que clasificaron los goles de las 380 partidas de la competicion con relacion al tiempo de incidencia, origen (balon parada o balanceo de la bola) y lugar de finalizacion (dentro o fuera del area penal). En total, se marcaron 1.034 goles. La mayor incidencia de goles fue en el segundo tiempo (579 goles, ~56%), principalmente en los ultimos quince minutos (221 goles, ~21%). En todos los periodos, la mayoria de los goles se origino en jugada con finalizacion en el area penal. Como conclusion, los resultados de este estudio indicaron que la mayor frecuencia de goles tiene lugar al final de las partidas, aunque los mejores equipos presenten mas regularidad en la distribucion de los goles a lo largo de la partida. Los equipos mejores clasificados al final de la competicion presentaron mas regularidad en la realizacion de goles entre los dos periodos.

Previous blood pressure measurement and associated factors in student adolescents.

Objective To identify prevalence of previous blood pressure measurement and analyze some associated factors in adolescents. Methods This cross-sectional study included 6,077 adolescents aged 14 to 19 years. Demographic characteristics included (sex, age, period of study, region of residence, work, skin color, and economic) status, history of blood pressure measurement within last 12 months, local of blood pressure measurement, and reading obtained. To assess associations between previous blood pressure measurement with demographic characteristics and high blood pressure we used descriptive statistics and logistic regression analysis. Results Out of the adolescents, 56.8% reported no blood pressure measurement within the last 12 months. The health centers and the physician’s office were most mentioned places for blood pressure measurement (28.3% and 36.9%, respectively). Boys (odds ratio of 1.64 95%CI: 1.46-1.84) aged 14 to 16 years (odds ratio of 1.12; 95%CI: 1.01-1.25), whose economic status was unfavorable (odds ratio of 1.48; 95%CI: 1.32-1.67) were significantly associated with no blood pressure measurement. Working was a protective factor for was not blood pressure measurement (odds ratio of 0.84; 95%CI: 0.73-0.97). Conclusion Most of adolescents did not have their blood pressure measured within the last 12 months. Boys aged 14 to 16 years and those with unfavorable economic status had higher chance of not having their blood pressure measured.

Relation between leukocyte count, adiposity, and cardiorespiratory fitness in pubertal adolescents

Objective To compare the total and differential leukocyte count in obese and normal-weight adolescents, and to verify their possible relations with cardiorespiratory fitness and adiposity indicators. Methods A cross-sectional study conducted with 139 adolescents (107 obese and 32 normal weight) aged between 13 and 18 years. Cardiorespiratory fitness was determined by direct gas analysis during an incremental treadmill test. Total leukocytes and subsets were estimated by flow cytometry. Body composition was assessed by dual-energy X-ray absorptiometry. The t-test for independent samples was used for comparison between groups. The relation between leukocytes, cardiorespiratory fitness and adiposity indicators was verified by Pearson’s correlation and multiple linear regression (adjusted for age and body mass index) tests. Results Obese adolescents had higher leukocyte (8.12±2.36u/L x 103; p=0.001), neutrophil (4.33±1.86u/L x 103; p=0.002), and monocyte (0.70±0.22u/L x 103; p=0.002) counts compared to the levels of normal weight subjects. After the necessary adjustments, cardiorespiratory fitness had a negative association with leukocytes, neutrophils, and monocytes in boys. Conclusion Obese adolescents had higher total and differential leucocyte count when compared to normal weight individuals. We also observed a weak positive association between adiposity and total leukocyte, monocyte, and neutrophil counts, and in boys, a negative association between cardiorespiratory fitness and total count of leukocytes, monocytes, and neutrophils.

Efeito do treinamento físico na pressão arterial de adolescentes com obesidade

Objective: To systematically review the results of studies that analyzed the effects of physical training on the blood pressure of obese adolescents. Data sources: A systematic review of randomized clinical trials was performed and examined the effect of physical training on the blood pressure of obese adolescents, published in journals indexed at PubMed/Medline, Lilacs, SciELO, and ISI Web of Knowledge SM databases. Studies that evaluated adolescents published until 2010 and that had a Control Group were included. Data synthesis: Eight studies met the inclusion criteria. Two of them used strength exercises combined with aerobics, while six used only aerobics. Five studies used complementary intervention, especially nutritional. Four studies found decreased systolic blood pressure in the Training Group compared to Controls, together with the reduction in body mass. All studies that found a reduction in systolic blood pressure used aerobic exercises from 12 to 24 weeks three to six times per week, lasting 50 to 90 minutes, and with intensity between 55 and 75% at the maximum heart rate. Conclusions: The effect of physical training on the systolic blood pressure of obese adolescents is controversial. However, the reduction in systolic blood pressure seems to occur with aerobic training programs, that also reduce body mass.OBJETIVO: Descrever, por meio de uma revisao sistematica, os efeitos do treinamento fisico sobre a pressao arterial em adolescentes com obesidade. FONTES DE DADOS: Recorreu-se a revisao sistematica de ensaios clinicos randomizados que analisaram o efeito do treinamento fisico sobre a pressao arterial de adolescentes obesos, publicados em periodicos indexados nas bases de dados PubMed/Medline, Lilacs, SciELO e ISI Web of KnowledgeSM. Foram incluidos os estudos que avaliaram adolescentes publicados ate 2010, e que possuiam Grupo Controle. SINTESE DOS DADOS: Oito estudos atenderam aos criterios de inclusao. Dois deles utilizaram exercicios de forca combinados com aerobios, enquanto seis empregaram apenas os aerobios. Cinco estudos utilizaram intervencoes complementares, sendo a nutricional a mais frequente. Quatro estudos observaram reducao da pressao arterial sistolica no Grupo Exercicio comparado ao Controle. Nesses quatro estudos, alem da reducao da pressao arterial, notou-se diminuicao da massa corporea. Todos aqueles que verificaram reducao da pressao arterial utilizaram 12 a 24 semanas de exercicios aerobios, tres a seis sessoes semanais, com duracao de 50 a 90 minutos e intensidade entre 55 e 75% da frequencia cardiaca maxima. CONCLUSOES: O efeito do treinamento fisico na pressao arterial de adolescentes obesos e controverso. A reducao da pressao arterial parece ocorrer com programas de treinamento aerobios que promovam tambem a reducao da massa corporea.